State wildlife officials are stepping up their efforts to track Florida panthers, a protected species that has been brought back from near extinction but is still struggling to thrive.

The species' numbers had been reduced to fewer than 20 adults by the 1970s, all in extreme South Florida.

The panther population is now estimated to be 100 to 160 adults and sub-adults -- meaning they left their mothers but have not yet reached sexual maturity.

The Florida Fish and Wildlife Conservation Commission is now working with the U.S. Fish Wildlife Service to document where panthers are roaming beyond South Florida, and to develop practices to help people and panthers coexist.

FWC also is asking for the general public's help.

The FWC has set up an area on its website, http://myfwc.com/, for people to submit panther photographs and other information to document panther sightings and habitat, said Kipp Frohlich, a section leader with the FWC's Imperiled Species Program.

This month, during a presentation to the FWC board, Frohlich said sightings of male panthers in North and Central Florida are increasing. In one case, a male cat was reported as far north as Georgia.

Tracking numbers for the male migration are an indication that panther recovery efforts are working. However, females are still remaining south of the Caloosahatchee River, Frohlich said.

FWC staff has not been able to officially document adult female panthers north of the Caloosahatchee River or Lake Okeechobee since the 1970s.

The FWC's panther management team uses data gathered from the capture and tracking of radio-collared panthers, the causes of panther mortalities and documentation of "denning" mothers to monitor population trends, changes in occupied range, and threats to the population.

"The good news is that the numbers are increasing," Frohlich said.

The ultimate goal of the Fish Wildlife Service's recovery plan is to have the panther population reach 240, which enables the "genetics to stay strong" and guarantee they will be around for at least 100 years, Frohlich said.

These efforts have helped the panther population rebound, but collisions with automobiles and having their habitat encroached upon by development are huge factors in limiting their full recovery, said FWC Chairman Kenneth Wright.

Wright cited cooperation with private landowners as a large part of the success.

Panthers need a large area to roam, as much as 200 square miles for an adult male. In South Florida, panthers have access to federally managed public lands such as Everglades National Park, Big Cypress National Preserve and the Panther National Wildlife Refuge, in addition to state and privately owned lands.

In the southern part of Central Florida, a key area for potential expansion of the large cat, more panther habitat is privately owned.

"We have room for more panther population growth as long as we manage areas successfully," said FWC Commissioner Ronald Bergeron, who suggested it should be a priority both to conserve the core population in South Florida and prepare for expansion north of the Caloosahatchee River. "We have to target the heart of where the panthers are, and continue to move forward with good habitat and with underpasses to protect panthers crossing highways."

In the coming months, the FWC will be collaborating with the public, including private landowners in Central Florida, about what information and resources they need to be prepared for an increased presence of panthers.

The FWC board supported this approach, particularly an exploration of what panther-related conservation incentives should be made available to landowners.

The panther was first protected under state law in 1958. It was first listed as endangered by the federal authorities in 1967 and included under the Endangered Species Act when the act was amended in 1973.

Upcoming research will address:

• Understanding and responding to the challenges of how people react to panther range expansion.

• Partnering with private landowners to study panthers' food habits and use of ranch lands.

• Refining methods to estimate panther numbers and population trends.

People can submit panther photographs and other information at http://myfwc.com, under the wildlife and habitats section.